Hello everyone, I'm new to this forum and have done a lot of research in the past and should first say thanks.

Now to my question. I've recently had some pinging issues arise in my 02' F150, 4.2 85k miles. Pinging only occurs when at operating temp, and moderate acceleration.
What I've done: Cleaned MAF, Changed DFPE, manually tested EGR, 2 seafoam treatments. No difference.

I just did a 'dynamic' vacuum test on the EVR Solenoid. I hooked up the vacuum inbetween the EVR Solenoid & the EGR. At no point during acceleration/driving did I get greater then 4mg hg of vacuum. I tested the vacuum line to the intake as well and got 15mghg at idle, and around 8 at the point where pinging starts.

Could someone tell me the amount of vacuum the egr should get during moderate throttle/2000 rpms at normal operating temp? Can an EVR Solenoid not work 100%? Is there any way to tell if it's getting bad info from the PCM and nothing to do with EVR?

Sorry for the long post and thanks for reading.

 

No help?

 

No CEL? or stored no/low flow codes for EGR?

Noidle concern, performance loss/driveabilty problems other than the ping?

 

Thank you for replying.

I had a CE light come on probably for two days total. IIRC the code was P0402. Nothing ever again (the CE light does work)

No performance symptoms whatsoever. The ping is greatly reduced with octane booster, and amongst other things is why I believe the egr system is at fault.

If I find the egr is supposed to get greater vacuum then 4mghg during any point of driving, I can attribute it to the evr solenoid, or the PCM. Unless I'm way off...

Is there a way to bench test an MAF sensor?

 

Have a scana tool put on it that can read the PID's. Look at the hertz reading and post back with that reading and your approximate altitude. As a reference, we are at approx. 1000 feet and out hertz reading is approximately 157. I will see if I can find the chart and post it here.

 

unfortunately Idon't have the equipment for that. I guess I'll be stopping by my local shop.

 

The P0402 is for excessive EGR flow at idle. The EGR vent or the DPFE may be the cause of that.

 

Known issue with the 4.2. Couple of thoughts to try.

Thought #1

TSB 07-16-17
TITLE
Spark knock under light loads and acceleration - 3.8L, 3.9L, and 4.2L - Split port intake manifold Runner Control ( IMRC ).

This TSB covers
FORD
2001-2004 Mustang
1996-2003 Windstar
1997-2003 E-150 and F -150
2004-2007 Freestar

MERCURY
2004-2007 Monterey

ISSUE
Various vehicles equipped with a 3.8L, 3.9L, or 4.2L engine and a Split Port IMRC may exhibit spark knock under light load and acceleration.

This bulletin has you look at the IMRC actuator Rods to see if they are connected properly and if not replace them and add new retainers clips.

Thought #2

You could also have eccessive build-up inside your intake from the oil vapors that are sucked into the intake via the PCV valve causing the problem.

 

Interesting. I will look into that TSB as soon as possible. Thank you for that information.

 

If you have a P0402, I would think that you have a faulty DPFE sensor. If, in fact, you did have excessive EGR flow at idle, your engine would stall. If the sensor was reading too high at idle, then the computor would not apply much vacuum at road speed, to keep the flow down. Now if you really didn't have high flow at idle, but the computor thought you did, it would restrict flow and that would give you a slight ping.